Underwater construction sometimes causes extraordinarily strong, albeit temporary, local noise in the marine area. Such impulsive noise has been shown to cause behavioural changes, physiological stress, physical damage and even mortality to, for example, fish and marine mammals. Moreover, the upcoming, increasing wind power construction is one of the major sources of impulsive noise, and it is therefore necessary to develop further actions to reduce impulsive noise. The two ongoing international research projects will chart the intensity, distribution, and impact of noise in the Baltic Sea.

The measure consists of the following actions:
1) Research information about the effects of impulsive noise will be put together.
2) Construction, blasting, and dredging activities causing impulsive noise are collected in a national register (e.g. HERTTA) where the source, intensity and time are registered. The register facilitates noise monitoring and specifies information on the level of noise in the marine areas.
3) Existing instructions for building of marine wind farms will be reviewed. Where appropriate, the instructions and recommended practises for e.g. a protection zone from which the animals are expelled, the duration of noise and the timing of the measures will be updated. Technical applications for noise reduction will also be introduced to reduce the effects of impulsive noise during construction.


Selvitystyö rekisterin käytöstä 2016–2018
Ohjeistusten laatiminen 2019–2021


Ministry of the Environment

Projects to be carried out under the measure

Determining the areas affected by underwater noise for the purposes of maritime spatial planning and mitigating adverse effectsToggle
Underwater noise mitigation – Pilot projectToggle
As part of Helsinki and Turku’s third Baltic Sea Action Plan 2019–2023, the cities will determine their underwater noise situation, identify and map areas and sites sensitive to underwater noise, collect information on underwater noise in major water construction and shipping lane projects and prepare further actions for reducing underwater noise (actions 46–49) (Baltic Sea Challenge).Toggle